(a) Nitrogen oxides (NOX ) emission specifications. The owner or operator of any utility boiler, auxiliary steam boiler, or stationary gas turbine subject to this division shall not allow the discharge into the atmosphere, emissions of NOX in excess of the following:
  (1) utility boilers:
    (A) 0.06 pounds per million British thermal units (lb/MMBtu) heat input from utility boilers that are part of a small utility system, as defined in §117.10 of this title (relating to Definitions):
      (i) on a rolling 24-hour average basis during the months of March through October of each calendar year; and
      (ii) on a rolling 30-day average basis during the months of November, December, January, and February of each calendar year;
    (B) 0.033 lb/MMBtu heat input from utility boilers that are part of a large utility system, as defined in §117.10 of this title:
      (i) on a rolling 24-hour average basis during the months of March through October of each calendar year; and
      (ii) on a rolling 30-day average basis during the months of November, December, January, and February of each calendar year;
    (C) 0.50 pounds per megawatt-hour output on an annual average basis; or
    (D) 0.033 lb/MMBtu heat input on a system-wide heat input weighted average basis for utility boilers that are part of a large utility system, as defined in §117.10 of this title:
      (i) on a rolling 168-hour average basis for each hour during which fuel was combusted in any unit in the system; and
      (ii) determined according to the following equation:
Attached Graphic
  (2) auxiliary steam boilers:
    (A) 0.26 lb/MMBtu heat input on a rolling 24-hour average and 0.20 lb/MMBtu heat input on a 30-day rolling average while firing natural gas or a combination of natural gas and waste oil;
    (B) 0.30 lb/MMBtu heat input on a rolling 24-hour averaging period while firing fuel oil only;
    (C) the heat input weighted average of the applicable emission specifications specified in subparagraphs (A) and (B) of this paragraph on a rolling 24-hour averaging period while firing a mixture of natural gas and fuel oil, as follows:
Attached Graphic
    (D) for each auxiliary steam boiler that is an affected facility as defined by New Source Performance Standards (NSPS) 40 Code of Federal Regulations Part 60, Subparts D, Db, or Dc, the applicable NSPS NOX emission limit, unless the boiler is also subject to a more stringent permit emission limit, in which case the more stringent emission limit applies. Each auxiliary steam boiler subject to an emission specification under this subparagraph is not subject to the emission specifications of subparagraphs (A), (B), or (C) of this paragraph.
  (3) stationary gas turbines:
    (A) with a megawatt (MW) rating greater than or equal to 30 MW and an annual electric output in megawatt-hr (MW-hr) of greater than or equal to the product of 2,500 hours and the MW rating of the unit, NOX emissions in excess of a block one-hour average of:
      (i) 42 parts per million by volume (ppmv) at 15% oxygen (O2), dry basis, while firing natural gas; and
      (ii) 65 ppmv at 15% O2, dry basis, while firing fuel oil; and
    (B) used for peaking service with an annual electric output in MW-hr of less than the product of 2,500 hours and the MW rating of the unit, NOX emissions in excess of a block one-hour average of:
      (i) 0.20 lb/MMBtu heat input while firing natural gas; and
      (ii) 0.30 lb/MMBtu heat input while firing fuel oil.
(b) Related emissions. The owner or operator of any unit subject to the emission specifications of subsection (a) of this section shall not allow emissions in excess of the following, except as provided in §117.1325 of this title (relating to Alternative Case Specific Specifications):
  (1) for utility boilers or auxiliary steam boilers, carbon monoxide (CO) emissions of 400 ppmv at 3.0% O2, dry (or alternatively, 0.30 lb/MMBtu heat input for gas-fired units and 0.31 lb/MMBtu heat input for oil-fired units), based on:
    (A) a block one-hour averaging period for units not equipped with a continuous emissions monitoring system (CEMS) or predictive emissions monitoring system (PEMS) for CO; and
    (B) a rolling 24-hour averaging period for units equipped with CEMS or PEMS for CO;
  (2) for any stationary gas turbine with a MW rating greater than or equal to 10 MW, CO emissions in excess of a block one-hour average of 132 ppmv at 15% O2, dry basis; and
  (3) for units that inject urea or ammonia into the exhaust stream for NOX control, ammonia emissions of 10 ppmv, at 3.0% O2, dry, for utility boilers or auxiliary steam boilers and 15% O2, dry, for stationary gas turbines (including duct burners used in turbine exhaust ducts), based on:
    (A) a block one-hour averaging period for units not equipped with a CEMS or PEMS for ammonia; and
    (B) a rolling 24-hour averaging period for units equipped with CEMS or PEMS for ammonia.
(c) Compliance flexibility.
  (1) An owner or operator may use §117.9800 of this title (relating to Use of Emission Credits for Compliance) to comply with the NOX emission specifications of this section.
  (2) Section 117.1325 of this title is not an applicable method of compliance with the NOX emission specifications of this section.
  (3) An owner or operator may petition the executive director for an alternative to the CO or ammonia specifications of this section in accordance with §117.1325 of this title.

Source Note: The provisions of this §117.1310 adopted to be effective June 14, 2007, 32 TexReg 3206; amended to be effective June 25, 2015, 40 TexReg 3965